If you tuned into The Daily Show recently, you would have heard Jon Stewart’s guest, David Agus, a physician and author of the new best-selling
book The End of Illness, fret about what could be called America’s
vitamin abuse problem.
There have been 50 large-scale
studies on supplements, he said, and not one has shown a benefit in heart
disease or cancer. “I don’t get it,” he said. “Why are we taking these?”
Agus is not alone in his
frustration. Other experts liken buying vitamins to flushing money down the
toilet. In some cases, they mean it literally: If the body gets more of certain
vitamins than it needs, it often excretes the excess in urine.
That doesn’t stop Americans from
spending about $28 billion a year on dietary supplements, including vitamins
and herbal supplements.
In some cases, people may be
spending money only to put their health at risk. “As Americans, we think more
is better, but that’s not the case with vitamins,” says Dee Sandquist, a
registered dietician and spokesperson for the Academy of Nutrition and
Dietetics. Here are three popular vitamin supplements that prove you can, in
fact, get too much of a good thing.
Supplement skeptics often point to the story of vitamin E,
which was once considered a promising tool for cancer prevention. The National
Cancer Institute was so hopeful that vitamin E supplements would decrease rates
of prostate cancer that in 2001 it funded a study designed to test the theory.
Instead, the findings revealed that the men who took vitamin E were 17 percent more
likely—not less—to develop the disease.
While vitamin E is a key player in
immune function and cell communication, it’s best obtained through diet—in foods like wheat germ, sunflower
seeds, and broccoli—and worst when taken regularly in high doses. Like many
vitamins, it appears to lose its main benefits when taken in excess.